That's a likely question to come up when one hears the news of AOL paying $850m to buy Bebo with its 40m uses.
However, it's a wrong question. Facebook and Bebo are not apples to apples.
Bebo is, by all means, a success. It successfully attacked international markets before Facebook was interested in them and before MySpace focused. However, at its core, Bebo is a media company.
I have been proposing that social networks have diverged into two paths. One is the media path. Led by MySpace (with its Entertainment company DNA), the media approach sees the users of a social network as an audience and is focused on creating and distributing content, usually sourced economically, to that audience. Others here include Bebo, Netlog, and Friendster.
The other path, with much fewer followers, is the one Facebook leads. It's the technology path. (Orkut has the right DNA to play here but Google could not make that happen). This model goes after the social graph, and the win is an infrastructure win: Adding an identity layer to the internet. The stakes are much higher. The players have to think of themselves as technology companies. Facebook is a technology company.
That's why the Bebo - Facebook comparison is the wrong one. Bebo priced its audience at $20-25/user. I would imagine, MySpace would price its audience around $50/user, getting a market leader premium. These are still big valuation bets on future monetization of the attention of these users.
Bebo must agree with me on some version of this thinking, otherwise it would not have settled on the audience pricing.